#ifndef __MTD_MTD_H__
#define __MTD_MTD_H__

#include <types.h>
#include <mtd/mtd-abi.h>

#define MAX_MTD_DEVICES 32

#define MTD_ERASE_PENDING   0x01
#define MTD_ERASING     0x02
#define MTD_ERASE_SUSPEND   0x04
#define MTD_ERASE_DONE      0x08
#define MTD_ERASE_FAILED    0x10

#define MTD_FAIL_ADDR_UNKNOWN -1LL

typedef enum {
    FL_READY,
    FL_STATUS,
    FL_CFI_QUERY,
    FL_JEDEC_QUERY,
    FL_ERASING,
    FL_ERASE_SUSPENDING,
    FL_ERASE_SUSPENDED,
    FL_WRITING,
    FL_WRITING_TO_BUFFER,
    FL_OTP_WRITE,
    FL_WRITE_SUSPENDING,
    FL_WRITE_SUSPENDED,
    FL_PM_SUSPENDED,
    FL_SYNCING,
    FL_UNLOADING,
    FL_LOCKING,
    FL_UNLOCKING,
    FL_POINT,
    FL_XIP_WHILE_ERASING,
    FL_XIP_WHILE_WRITING,
    FL_SHUTDOWN,
    /* These 2 come from nand_state_t, which has been unified here */
    FL_READING,
    FL_CACHEDPRG,
    /* These 4 come from onenand_state_t, which has been unified here */
    FL_RESETING,
    FL_OTPING,
    FL_PREPARING_ERASE,
    FL_VERIFYING_ERASE,

    FL_UNKNOWN
} flstate_t;

/*
 * If the erase fails, fail_addr might indicate exactly which block failed. If
 * fail_addr = MTD_FAIL_ADDR_UNKNOWN, the failure was not at the device level
 * or was not specific to any particular block.
 */
struct erase_info {
    struct mtd_info *mtd;
    uint64_t addr;
    uint64_t len;
    uint64_t fail_addr;
#ifndef __MBOOT__
    u_long time;
    u_long retries;
    unsigned dev;
    unsigned cell; 
    void (*callback) (struct erase_info *self);
    u_long priv;
#endif
    u_char state;
#ifndef __MBOOT__
    struct erase_info *next;
#endif
};  

/**
 * struct mtd_oob_ops - oob operation operands
 * @mode:   operation mode
 *
 * @len:    number of data bytes to write/read
 *
 * @retlen: number of data bytes written/read
 *  
 * @ooblen: number of oob bytes to write/read
 * @oobretlen:  number of oob bytes written/read
 * @ooboffs:    offset of oob data in the oob area (only relevant when
 *      mode = MTD_OPS_PLACE_OOB or MTD_OPS_RAW)
 * @datbuf: data buffer - if NULL only oob data are read/written
 * @oobbuf: oob data buffer
 *
 * Note, it is allowed to read more than one OOB area at one go, but not write.
 * The interface assumes that the OOB write requests program only one page's
 * OOB area. 
 */ 
struct mtd_oob_ops {
    unsigned int    mode;
    size_t      len;
    size_t      retlen;
    size_t      ooblen;
    size_t      oobretlen;
    uint32_t    ooboffs;
    uint8_t     *datbuf;
    uint8_t     *oobbuf;
};

#define MTD_MAX_OOBFREE_ENTRIES_LARGE   32
#define MTD_MAX_ECCPOS_ENTRIES_LARGE    448
/*  
 * Internal ECC layout control structure. For historical reasons, there is a
 * similar, smaller struct nand_ecclayout_user (in mtd-abi.h) that is retained
 * for export to user-space via the ECCGETLAYOUT ioctl.
 * nand_ecclayout should be expandable in the future simply by the above macros.
 */ 
struct nand_ecclayout {
    __u32 eccbytes;
    __u32 eccpos[MTD_MAX_ECCPOS_ENTRIES_LARGE];
    __u32 oobavail;
    struct nand_oobfree oobfree[MTD_MAX_OOBFREE_ENTRIES_LARGE];
};

struct mtd_info {
    u_char type;
    uint32_t flags;
    uint64_t size;   // Total size of the MTD

    /* "Major" erase size for the device. Naïve users may take this
     * to be the only erase size available, or may use the more detailed
     * information below if they desire
     */
    uint32_t erasesize;
    /* Minimal writable flash unit size. In case of NOR flash it is 1 (even
     * though individual bits can be cleared), in case of NAND flash it is
     * one NAND page (or half, or one-fourths of it), in case of ECC-ed NOR
     * it is of ECC block size, etc. It is illegal to have writesize = 0.
     * Any driver registering a struct mtd_info must ensure a writesize of
     * 1 or larger.
     */
    uint32_t writesize;

    /*
     * Size of the write buffer used by the MTD. MTD devices having a write
     * buffer can write multiple writesize chunks at a time. E.g. while
     * writing 4 * writesize bytes to a device with 2 * writesize bytes
     * buffer the MTD driver can (but doesn't have to) do 2 writesize
     * operations, but not 4. Currently, all NANDs have writebufsize
     * equivalent to writesize (NAND page size). Some NOR flashes do have
     * writebufsize greater than writesize.
     */
    uint32_t writebufsize;

    uint32_t oobsize;   // Amount of OOB data per block (e.g. 16)
    uint32_t oobavail;  // Available OOB bytes per block

    /*
     * If erasesize is a power of 2 then the shift is stored in
     * erasesize_shift otherwise erasesize_shift is zero. Ditto writesize.
     */
    unsigned int erasesize_shift;
    unsigned int writesize_shift;
    /* Masks based on erasesize_shift and writesize_shift */
    unsigned int erasesize_mask;
    unsigned int writesize_mask;

    // Kernel-only stuff starts here.
    const char *name;
    int index;

    /* ECC layout structure pointer - read only! */
    struct nand_ecclayout *ecclayout;

    /* Data for variable erase regions. If numeraseregions is zero,
     * it means that the whole device has erasesize as given above.
     */
    int numeraseregions;
    struct mtd_erase_region_info *eraseregions;

    /*
     * Erase is an asynchronous operation.  Device drivers are supposed
     * to call instr->callback() whenever the operation completes, even
     * if it completes with a failure.
     * Callers are supposed to pass a callback function and wait for it
     * to be called before writing to the block.
     */
    int (*erase) (struct mtd_info *mtd, struct erase_info *instr);

#ifndef __MBOOT__
    /* This stuff for eXecute-In-Place */
    /* phys is optional and may be set to NULL */
    int (*point) (struct mtd_info *mtd, loff_t from, size_t len,
            size_t *retlen, void **virt, resource_size_t *phys);

    /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
    void (*unpoint) (struct mtd_info *mtd, loff_t from, size_t len);

    /* Allow NOMMU mmap() to directly map the device (if not NULL)
     * - return the address to which the offset maps
     * - return -ENOSYS to indicate refusal to do the mapping
     */
    unsigned long (*get_unmapped_area) (struct mtd_info *mtd,
                        unsigned long len,
                        unsigned long offset,
                        unsigned long flags);

    /* Backing device capabilities for this device
     * - provides mmap capabilities
     */
    struct backing_dev_info *backing_dev_info;
#endif

    int (*read) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
    int (*write) (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf);

#ifndef __MBOOT__
    /* In blackbox flight recorder like scenarios we want to make successful
       writes in interrupt context. panic_write() is only intended to be
       called when its known the kernel is about to panic and we need the
       write to succeed. Since the kernel is not going to be running for much
       longer, this function can break locks and delay to ensure the write
       succeeds (but not sleep). */
    int (*panic_write) (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf);
#endif

    int (*read_oob) (struct mtd_info *mtd, loff_t from,
             struct mtd_oob_ops *ops);
    int (*write_oob) (struct mtd_info *mtd, loff_t to,
             struct mtd_oob_ops *ops);

#ifndef __MBOOT__
    /*
     * Methods to access the protection register area, present in some
     * flash devices. The user data is one time programmable but the
     * factory data is read only.
     */
    int (*get_fact_prot_info) (struct mtd_info *mtd, struct otp_info *buf, size_t len);
    int (*read_fact_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
    int (*get_user_prot_info) (struct mtd_info *mtd, struct otp_info *buf, size_t len);
    int (*read_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
    int (*write_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
    int (*lock_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len);

    /* kvec-based read/write methods.
       NB: The 'count' parameter is the number of _vectors_, each of
       which contains an (ofs, len) tuple.
    */
    int (*writev) (struct mtd_info *mtd, const struct kvec *vecs, unsigned long count, loff_t to, size_t *retlen);

    /* Sync */
    void (*sync) (struct mtd_info *mtd);

    /* Chip-supported device locking */
    int (*lock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
    int (*unlock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
    int (*is_locked) (struct mtd_info *mtd, loff_t ofs, uint64_t len);

    /* Power Management functions */
    int (*suspend) (struct mtd_info *mtd);
    void (*resume) (struct mtd_info *mtd);
#endif

    /* Bad block management functions */
    int (*block_isbad) (struct mtd_info *mtd, loff_t ofs);
    int (*block_markbad) (struct mtd_info *mtd, loff_t ofs);

#ifndef __MBOOT__
    struct notifier_block reboot_notifier;  /* default mode before reboot */
#endif

    /* ECC status information */
    struct mtd_ecc_stats ecc_stats;
#ifndef __MBOOT__
    /* Subpage shift (NAND) */
    int subpage_sft;
#endif

    void *priv;

#ifndef __MBOOT__
    struct module *owner;
    struct device dev;
#endif
    int usecount;

#ifndef __MBOOT__
    /* If the driver is something smart, like UBI, it may need to maintain
     * its own reference counting. The below functions are only for driver.
     * The driver may register its callbacks. These callbacks are not
     * supposed to be called by MTD users */
    int (*get_device) (struct mtd_info *mtd);
    void (*put_device) (struct mtd_info *mtd);
#endif
};

#endif /* __MTD_MTD_H__ */

